The objectives of this grant continue to be the investigation of angiographic methods of coronary artery lesions in human subjects with atypical chest pain, hyperlipemia and angina pectoris and by measuring flow at operation during myocardial revascularization with an electromagnetic flowmeter. We have repeated coronary arteriograms in many subjects, and find generally that the lesions become more severe and extensive. The results of coronary artery surgery and myocardial revascularization are being followed in an attempt to evaluate their efficacy; both clinically and by angiographic methods. We have been measuring regional myocardial flow at operation in human subjects with coronary disease. Our studies of the systemic and coronary hemodynamic effects of pharmacologic agents continue in animals hoping to clarify their mechanism of action. Coronary flow is being studied using electromagnetic flowmeters, a thermodilution flowmeter and the nitrous oxide method. These studies include systemic hemodynamics.